Busy morning here in the weather office this morning and all the talk on the blogs and discussion boards are on the tropics so lets get right to it and look at the latest.

INVEST 92L:

(Enhanced Infrared Satellite - Image Courtesy: Weather Underground)

THIS MORNING:
There has been a lot of deep convection (thunderstorms) developing with 92L over the past 12-18 hours and the disturbance looks much better developed this morning than it has since it moved off the coast of Africa. 92L is not far from becoming a depression or even a tropical storm. There are good indications of a near surface circulation center and the deep convection has been migrating closer to what appears to be the broad center. Upper level outflow is visible in the cirrus bands of clouds to the north and east. The current wind shear overhead is very weak and the water warm so this should be the onset of a gradual strengthening cycle. 92L has already begun to spread showers over the northern Leeward Islands, British and U.S. Virgin Islands. There will be an increase in showers and storms over Puerto Rico today ahead of the system.

THE TRACK FORECAST:


(Tropical Forecast Models - Image Courtesy: Colorado State University)

A look at the forecast shows more and more agreement in the overall potential track. The morning model guidance has a better grasp on 92L since it is better developed. They all show a continued WNW movement through about 72 hours. This brings the system very near the northern coast of Puerto Rico and Hispaniola. It remains to be seen if the rugged, mountainous terrain of these islands will have any profound effect on the development of the system. After the 72 hour mark is when we have to watch with caution. All the tropical model suites turn the system more poleward in response to a trough over the east-central U.S.. Timing is key on this turn. If the rightward jog happens later than currently forecast, it will pose a more significant risk to the Florida east coast and eventually the Georgia and South Carolina coasts. If the turn is sooner, 92L will move more parallel to the East Coast (fingers crossed!) The chances of this becoming a Gulf of Mexico storm are looking less and less today but as we always say with tropical systems, they make their own weather and go where they want to go. Needless to say…everyone from the Florida Keys to the Carolinas will be watching this one over the weekend.
THE INTENSITY FORECAST:
As good as we have gotten at track forecasting, we still lack in the area of intensity forecasting. We have several good models that work on this but so far out in advance it’s almost a general “shot in the dark”. Here is the latest guidance from CSU:

(Tropical Intensity Forecast - Image Courtesy: Colorado State University)

As you can see, the plots are across the board from a strong tropical storm to a Category 2 hurricane! All the “reliable” models that we lean on do bring 92L to hurricane status over the weekend and continue a upward trend at the end of the 120 forecast period. I feel somewhat ok with leaning toward the idea of a borderline Cat 1/2 by Monday…if the system continues to stay orginized today and does not become weakened by the terrain of the islands.
OUR BEST GUESS:
So all this leads us to our daily “best guess” on what will happen.  Seeing that 92L is looking good this morning and there is no reason for that to change, we will go with gradual strengthening into a depression or storm in the next 12-24 hours. A track just north of the islands looks prudent, based on the model guidance and we will go along with the current intensity guides as well, putting an Category 2 hurricane in the Bahamas over the weekend. Beyond that, I am not ready to make a call just yet. Do we need to be on “guarded watch” over the weekend? Absolutely. If the storm does recurve to the north, the odds are high that the Carolinas will suffer some effects…something that will continue to play out day by day and as always, we will be watching.

ELSEWHERE:
Invest 93L is very weak this morning and shows little signs of organization. The odds are low now that this disturbance will be a threat at all, even if it does develop. Forecast models also try and develop another wave off the African coast in 3-4 days from now.
Stay with is for more updates!

Chad Watson
Live 5 Meteorologist

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